Chair back

ABSTRACT

The design is the features of shape and ornament of the chair back as shown in solid lines in the drawings.

FIG. 1 is a front perspective view of a design for a chair back;

FIG. 2 is a front elevational view of the design shown in FIG. 1;

FIG. 3 is a bottom elevational view of the design shown in FIG. 1;

FIG. 4 is a side elevational view of the design shown in FIG. 1 in which the opposite side is a mirror image;

FIG. 5 is a top elevational view of the design shown in FIG. 1; and,

FIG. 6 is a perspective view of a chair incorporating the chair back of the present design in which the chair components shown in broken lines are environmental structure for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a chair back, as shown and described. 